Graphene-analogue molybdenum disulfide for adsorptive removal of tetracycline from aqueous solution: equilibrium, kinetic, and thermodynamic studies.

The performance of graphene-analogue molybdenum disulfide (G-MoS₂) as an adsorbent for removal of organic contaminant tetracycline from aqueous solution was studied systematically. The synthetic G-MoS₂ showed much better adsorption ability than the commercial MoS₂ with more than 90% of tetracycline removal. The kinetics data agreed well with the pseudo-second order model, and the equilibrium was obtained within 16 h. Langmuir isotherm model provided the best fit to the equilibrium data of tetracycline adsorption than Freundlich and Tempkin models. The adsorption was a spontaneous and endothermic process deduced by the thermodynamic analysis. Adsorption of tetracycline on G-MoS₂ was partly dependent on pH values, but strongly relied on ionic strength. The proposed mechanism was probably synergetic π-π dispersion, hydrophobic effect, and electrostatic interaction. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 815-821, 2017 [ABSTRACT FROM AUTHOR]